Control field surface member



J. P. WILSON 2,300,756

CONTROL FIELD SURFACE MEMBER Nov. 3, 1942.

Filed March 22, 1940- |';'u llll l fig 2 8 Jase 72 B Mlson,

Patented Nov. 3, 1942 UNETED STATES or'FicE-f- The invention relates to means for producing effects in response to the influence of the hand of a person or the body of a person, when brought within a predetermined area of influence. Such a device usually includes an oscillating electrical system including a capacitative device of such nature that proximity of the human body or a hand of a person will vary the effectiveness of the current passing passed in the system, so that it may operate a relay device by which other mechanisms or devices may be operated or energized. Usually, in such devices some means is employed to indicate approximately the space into which the body or hand may be introduced to control the device, and while it is not necessary for the body or the hand to be brought into contact with such area indicating device, on account of the ignorance or inclination of the general public, a great many persons will place the hand directly upon the apparatus or device by which the sensitive area is indicated. As the apparatus is usually enclosed in a cabinet, in some forms, the means by which the capacitative field is indicated may consist of an ornamental panel, or may consist of a plate glass Window in the cabinet or at a distance therefrom, and in other cases the panel may be an opaque or translucent element lacking in transparency. When persons have placed their hands against such glass or other panel made of smooth materials, finger-prints and smears appear, which are repulsive to subsequent observers who might wish otherwise to demonstrate the apparatus by the extension of their hand, and who might think it necessary to place the hand against the panel or the like. In addition, the panel surface or glass, whether transparent or translucent or opaque, tends to acquire a dirty appearance.

It is therefore an important aim of this invention to present a means by which a panel, or light-transmitting plate or material may be used to indicate the field into which the hand of the observer may be brought to cause the operation of the relay, and which will prevent the formation of finger-prints, or smears, or the accumulation of dirt in such manner as to be apparent to subsequent observers.

It is also an important aim of the invention to present means by which the field indicating device may be caused to present mystical effects.

Additional objects, advantages and features of invention reside in the construction, arrangement and combination of elements involved in the embodiment of the invention, as will be more readily understood from the following description and accompanying drawing, wherein Figure 1 is a front elevation of a panel element suitable for the uses indicated, adapted to be mounted in the side of a cabinet, or its essential parts incorporated in or upon a window, such as a show window or the like;

Figure 2 is a vertical cross section thereof.

Referring more particularly to the drawing, there is illustrated a control field assembly suitable for use with various devices, and especially for oscillating circuits including a capacitative control element, the details of which involve structural details which do not comprise the novel part of the present invention, and may be embodied in various forms, as understood in the art, as for example, in the patent to Theremin, No. 1,658,953.

This unit comprises an outer wall or case element iii, of non-conductivematerial,which may be opaque or transparent, but in the present instance is shown as a plastic body which may be colored or otherwise ornamented. It is 'here shown in the form of a rectangular plate having a rectangular opening 580, therethrough (although these forms may be varied without aifecting the function), the sides of which are parallel to those of the plate l8 and suitably spaced therefrom so as to give an adequate area of the plate l8 around ments described receive therethrough a block or plate 2 of glass or other light-transmitting material, substantially planiform but characterized throughout by small protuberances or nodules on its front face, and intervening indentations or re-v cesses [9, so that the entire surface is broken up into small irregularities, whereby a continuous surface such as could receive finger-prints of distinguishable pattern is avoided, and the nodules or protuberances are of sumcient elevation to prevent contact with the recessed parts by the epidermis or skin of the finger of a person touched thereupon. This front face portion of the plate 2 in the present instance conforms generally to the plane of, and is substantially flush with, the front face of the case element [8. The rear face of theplate 2 may be planiform, and may be flush with the rear face of the plate I, as shown in Figure 2, although this is not essential. Laid directly against the rear face of the plate 2, there is a transparent mirror film Id, of suitable material, back of which there is a series of transparent color elements I5 laid side by side directly against the mirror element, and embodying such colors as desired and most appropriate to the uses contemplated. These are protected and held in place by means of a wire mesh screen or the like l6, suitably connected to the plate I beyond the plate 2, substantially as indicated at H in Figure 2.

In accordance with well understood principles of electricity, the control field member I is utilized as one plate of a condenser or as an antenna, be-

ceiving a finger print impression of recognizablev extent and all arranged so that a finger pressed ing connected by the lead wire 3 in series with a conventional inductance 25 and bridging condenser 25a, the opposite terminal of the inductance being grounded, as indicated; so that if any person standing upon the ground holds his hand adjacent the field piece I, or places his hand adjacent or on the plate 2, a capacitative effect is set up, which modifies the effect of the inductance, and so enables control of the familiar relay devices, as is well understood.

It will be appreciated that the colored lighttransmitting elements I6 are capable of transmitting light forwardly from the rear through the film l4 and block 2, but the mirror film will reflect forwardly light entering through the front face of the member 2. a

It will be apparent that when the light is transmitted through the plate 2, the irregularities of the front surface of the block will so retract and disrupt the transmitted light that any deposits from the hands of previous users will be rendered still less obvious. This plate 2 may consist of some of the commercial forms of glass now available on the open market, such as ribbed glass and moss glass, two largely used patterns.

I claim:

1. A control field surface member for systems of the character described consisting of a body of material having a front face shaped with a multiplicity of small, very closely spaced protuberthereon will form only irregularly fragmented finger print patterns, and a metallic plate cooperatively associated with said body.

3. The surface member of claim 2 formed of light-transmitting and refracting material and having a substantially smooth rear face, and a transparent mirror at the back of the said surface member.

4. The structure of claim 2' in which said surface member is formed of light-transmitting material, a transparent mirror located at the back of the said surface member, and a plurality of colored light-transmitting elements back of the mirror.

5. The structure of claim 2, in which said surface member is a light-transmitting material, and said metallic plate is shaped to surround the area of said surface member and having an opening therethrough for passage of light to and from a substantial area of said surface member.

6. The structure of claim 2 in which said surface member is a light transmitting material, and said metallic plate is shaped to surround the area of said surface member and having an opening therethrough for passage of light to and from a substantial area of said surface member, and a foraminate metallic member extending across the opening of said plate rearwardly of the surface member and electrically connected to said plate.

JOSEPH P. WILSON. 

